Keratoconus

Intrastromal corneal ring segments are plastic ring segments that are inserted in the cornea of Keratoconus patients using laser technology in order to flatten and regularize the corneal shape, and subsequently, improve vision. They are made of the same material that can be found in intraocular lenses placed during cataract surgery.

Corneal ring segments

Surgical procedure

Channels are created in the cornea using a specialized femtosecond laser system. The intracorneal ring segments are inserted through the laser-created channels. Once in, the cornea tends to flatten and regularize within a few days to few weeks, and sometimes up to 6 months. Vision subsequently improves, as does the refractive error. Intracorneal ring segments insertion is a short and easy procedure performed in the laser suite, under local topical anesthesia. examples of commonly used corneal rings include INTACS SK, Ferrara rings,
and Kerarings.

Post-operative recovery

Patients can resume normal activity like driving, office and computer work, one or two days later, and their vision usually improves over the next several days or weeks, and up to 6 months.
Patients should avoid rubbing their eyes and should avoid putting eye make-up and swimming for 1 month. Antibiotic and steroid eye drops and tear drops should be used 4 times a day for 10 days. Intracorneal rings are hardly noticeable on casual looks, but might be apparent to the astute observer on close-up scrutiny.

Results

Success & safety

The success rate of the corneal ring segment procedure is considered high; the improvement, however, is not necessarily total, and is not always guaranteed. Studies have shown that around 80% of patients do improve significantly. Improvement is defined by better vision and visual quality with or without eyeglasses, a lower refractive error in terms of myopia and astigmatism, or less or no dependency on hard or hybrid contact lenses. Some patients, previously intolerant to hard/hybrid lenses, get to tolerate them again due to corneal flattening and improvement in corneal shape. Ring segments do not usually stop disease progression; they mainly enhance corneal shape and improve vision.

Safety

Corneal ring segments insertion is a very safe and reversible procedure with a high success rate, a very short intra-operative time, and fast visual recovery. Potential side effects are rare, and include infection, ring extrusion, and mild halo around lights at night.